Many different items manufactured around the world are shipped in small and large cargo containers. These cargo containers often contain hundreds and thousands of items in packages and a variety of smaller boxes and containers. In some cases, the cargo containers are moved directly between ships at port while in other cases they may travel over land on trains and trucks to then be reloaded on ships or other transportation. Many of the items shipped in this manner arrive at their destination as planned and the shipping is considered successful.
Unfortunately, there are also times that items to be shipped do not make it to their destination as planned. In some cases, the items meant to be packed in a container are never actually loaded. If this occurs, the recipient of a shipment may not even discover the items are missing until after the inventory has been received and the items counted. Further, it is also possible that containers may be vandalized and certain items stolen or even replaced with inferior goods or knock-offs. In either of these scenarios, it helps to quickly determine when items have been stolen or swapped as missing items or knock-offs may go undetected for days or years.
Given the enormous quantities of items being shipped and transported, accurately detecting and tracking items is difficult if not impossible. Hundreds and thousands of items in large standardized shipping containers would be delayed several days or weeks in each port as items are inventoried using manual or even semi-automatic inventory methods and equipment. Alternatively, estimating the number of items contained in boxes, pallets or shipping container is faster but the results are also not acceptable given the inaccuracies and potential lost revenues from making such estimations. Accordingly, the costs, delay and inaccuracies associated with any of the current approaches for tracking and inventorying items remains unacceptable.
Like reference numbers and designations in the various drawings indicate like elements.